Barbeque grills are quite popular and in widespread use to cook food outdoors typically in a recreational setting. Heat is provided in a barbeque grill by means of a propane gas burner which heats ceramic briquettes or by means of lighted charcoal briquettes. Grates are mounted within the grill above the heat source and receive the food items to be cooked.
The barbeque grill grate is an important part of the grilling process and should be durable and provide good heat transfer. Typically grill grates are either cast iron, porcelain-coated steel or stainless steel. Over time, the repeated heating and cooling of the grate causes chips to form in porcelain grates and the thinness of steel grates causes them to degrade over a relatively short period of time. Normally these types of grates wear out or are rendered unusable well before the useful life of the barbeque grill itself and must be replaced. Cast iron grates are quite durable with a long useful life, but historically have been manufactured in a size to fit only a particular grill.
Since barbeque grills come in a multitude of sizes, it is desirable for replacement grates to be expandable. For a grate to be adaptable to various size grills, the grate not only needs to be expandable but also optimally should provide a cooking surface over the entire length of the grate, including the expansion area.